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991.
992.
微波法处理含铬废渣的可行性分析 总被引:1,自引:0,他引:1
微波辐照解毒铬渣是一项新技术,为考察该技术应用的可行性,本文对铬渣解毒前后性状的变化进行了讨论。结果表明,该技术能较完全地使高价铬转化为低价铬,解毒渣中铬主要以三价形态存在,铬渣毒性得到消除;解毒渣浸出液中Cr6+浓度远低于国家危险废物鉴别标准,解毒渣已不属于危险固体废弃物,其在环境条件下可安全存放。说明该技术具有应用前景。 相似文献
993.
A azoreductase gene with 537 bp was obtained by PCR amplification from Rhodobacter sphaeroides ASI. 1737. The enzyme,with a molecular weight of 18.7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage. 相似文献
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In situ iron activated persulfate oxidative fluid sparging treatment of TCE contamination--a proof of concept study 总被引:1,自引:0,他引:1
In situ chemical oxidation (ISCO) is considered a reliable technology to treat groundwater contaminated with high concentrations of organic contaminants. An ISCO oxidant, persulfate anion (S(2)O(8)(2-)) can be activated by ferrous ion (Fe(2+)) to generate sulfate radicals (E(o)=2.6 V), which are capable of destroying trichloroethylene (TCE). The property of polarity inhibits S(2)O(8)(2-) or sulfate radical (SO(4)(-)) from effectively oxidizing separate phase TCE, a dense non-aqueous phase liquid (DNAPL). Thus the oxidation primarily takes place in the aqueous phase where TCE is dissolved. A bench column study was conducted to demonstrate a conceptual remediation method by flushing either S(2)O(8)(2-) or Fe(2+) through a soil column, where the TCE DNAPL was present, and passing the dissolved mixture through either a Fe(2+) or S(2)O(8)(2-) fluid sparging curtain. Also, the effect of a solubility enhancing chemical, hydroxypropyl-beta-cyclodextrin (HPCD), was tested to evaluate its ability to increase the aqueous TCE concentration. Both flushing arrangements may result in similar TCE degradation efficiencies of 35% to 42% estimated by the ratio of TCE degraded/(TCE degraded+TCE remained in effluent) and degradation byproduct chloride generation rates of 4.9 to 7.6 mg Cl(-) per soil column pore volume. The addition of HPCD did greatly increase the aqueous TCE concentration. However, the TCE degradation efficiency decreased because the TCE degradation was a lower percentage of the relatively greater amount of dissolved TCE by HPCD. This conceptual treatment may serve as a reference for potential on-site application. 相似文献
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The determination of trace amount nitrobenzene in wastewater on a hanging mercury drop electrode was studied. The determination
conditions of pH, supporting electrolyte, accumulation potential, accumulation time, and voltammetric response were optimized.
The sharp peak of the nitrobenzene was appeared at 0.05 V. The peak electric current was proportional to the concentration
of nitrobenzene in the range of 1.47 × 10−5 ∼ 1.0 × 10−3 mol/l with relative standard deviations of 3.99 ∼ 8.94%. The detection limit of the nitrobenzene in water was 5 × 10−6 mol/l. The proposed method offered low limit of determination, easy operation, the use of simple instrumentation, high sensitivity
and good reproducibility. It was applied to the determination of nitrobenzene in wastewater with an average recovery of 94.0%
∼ 105%. The proposed method provided fast, sensitive and sometimes real time detection of nitrobenzene. 相似文献